You are importing a large CSV file and using the auto-import option but an alert is displayed:
This alert informs you that the settings used are not optimized enough to suit your server's resources:
The number of lines entered cannot be processed within the time interval configured.
In the above example, 500 lines to be processed in 5 seconds.
You therefore need to either increase the time interval or reduce the number of lines to be processed in that time.
Please refer to this article for more information on the auto-import option.